Tissue expansion device

ABSTRACT

A tissue expansion device can be implanted temporarily beneath skin of a patient and removed upon expansion of overlying tissue. The device can include an expandable shell having a smooth or glossy outer surface and an injection port. The expandable shell can form an expandable chamber and have an anterior portion and a posterior portion. The injection port can be coupled to the anterior portion of the shell and be in fluid communication with the chamber and configured to permit injection of fluid into the chamber from a hypodermic needle. The device can have a plurality of tabs coupled to the posterior portion of the shell having one or more colors or attributes. The device can also include an orientation indicator visible along the anterior portion of the shell for assisting a clinician and orienting the device during the implantation procedure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/571,036, entitled “TISSUE EXPANSION DEVICE,” filed on Sep. 13, 2019,which claims the benefit of U.S. Provisional Application No. 62/731,033,entitled “TISSUE EXPANSION DEVICE,” filed Sep. 13, 2018, the disclosureof each of which is incorporated herein by reference in its entirety.

BACKGROUND

The present disclosure relates generally to systems and methods fortissue expansion, and more particularly, to expanding the tissue of apatient in preparation for receiving an implant.

Implantable prostheses are commonly used to replace or augment bodytissue. In the case of breast cancer, a mastectomy is sometimesnecessary to remove some or all of the mammary gland and surroundingtissue, which creates a void. This void may be filled with afluid-filled implantable prosthesis. The implant serves to supportsurrounding tissue and to maintain the appearance of the body. Therestoration of the normal appearance of the body has an extremelybeneficial psychological effect on post-operative patients, alleviatingmuch of the shock and depression that often follows extensive surgicalprocedures.

Soft implantable prostheses typically include a relatively thin andquite flexible envelope or shell made of silicone elastomer. The shellis filled either with a silicone gel or with a physiologic salinesolution. The filling of the shell may take place before or after theshell is implanted in the patient.

A saline-filled implant includes an outer shell of several layers ofsilicone elastomer having a valve or fill port on one side. Theprosthesis is typically implanted into the breast cavity in an empty oronly partially filled state. The implant is then inflated to its finalsize by means of the valve or fill port. This helps reduce the size ofthe needed incision, and enables a surgeon to adjust and evenmicroadjust the volume of the implant.

In breast reconstruction, prior to implantation of a long-termprosthesis, it is common practice to utilize a more temporary implant,for example, what is known as a “tissue expander” or “tissue expansiondevice” in order to gradually create the space necessary for thelong-term prosthesis. For example, in some situations, such as amastectomy, the chest tissues may be flat and tight, and an expander canserve to prepare the body for receiving a long-term prosthesis. Tissueexpanders can also be used in other places in the body to expand healthytissue to replace a nearby defect such as a burn or scar. Essentially, atissue expansion device comprises an inflatable body, having aninflation valve connected thereto. The valve may be formed into theinflatable body itself or may be remotely located and connected to theinflatable body by means of an elongated conduit.

The inflatable body of the tissue expansion device is placedsubcutaneously in the patient, at the location of where tissue is to beexpanded. The inflation valve, whether on the implant or remote thereto,is also subcutaneously positioned or implanted, and is configured toallow gradual introduction of fluid, typically saline, into theinflation body, by injection with a syringe. After gradual inflation atpre-determined intervals, the skin and subcutaneous tissues overlyingthe expander are consequently caused to expand in response to thepressure exerted upon such tissues by the inflatable body as solution isgradually introduced therein.

After gradual inflation at pre-determined intervals, which may extendover weeks or months, the skin and subcutaneous tissue will expand tothe point where further medical procedures can be performed, such as theimplantation of a long-term prosthesis, plastic and reconstructivesurgery, or for use of the skin and subcutaneous tissue for use in someother part of the body.

SUMMARY

The present application discloses various improvements for tissueexpansion devices and related procedures that can be used to treathumans and/or animals. The devices and procedures can be used, forexample, in the context of breast reconstruction surgery, breastaugmentation surgery, and skin graft surgery.

Implantable devices, such as breast implants and tissue expansiondevices, can be round or anatomically shaped. In accordance with anaspect of at least some of the embodiments disclosed herein is therealization that if anatomically shaped, breast implants are generallysymmetrical about a centerline and therefore, require the surgeon to beaware of that centerline so the device is implanted in the properorientation.

In accordance with some embodiments disclosed herein, a tissue expansiondevice can be configured in a manner that improves on the current stateof the art by providing more effective and more economical orientationmeans. For example, instead of applying a separate material, such as astrip of contrasting colored material to the shell in a manufacturingstep separate from the creation of the shell of the implant, the presentdisclosure provides devices and methods that can provide a visuallycontrasting line on the shell during the casting/molding process of thesilicone shell.

For example, in some embodiments, a shell casting tool can be providedto create a tissue expansion device, whether it is a mold or a mandrel,which can be finished with a surface that is roughened, by sandblastingor other means, except for the desired orientation line feature which isleft as a polished or glossy surface. The resulting silicone shell madefrom this tool can then inherently and clearly illustrate these twodifferent surface finishes by providing a contrasting visibleorientation line on the shell surface without additional components orassembly steps.

Optionally, in at least one embodiment, a tissue expansion device can beprovided that comprises suture tabs placed around the periphery to helpstabilize the device position upon implantation. Suture tabs can bepositioned, for example, at the 6 or 12 o'clock position to provide ameans of visual orientation for the clinician.

However, in accordance with at least some embodiments disclosed hereinis the realization that if all the suture tabs appear the same, as intraditional devices, it is possible to inadvertently slightly rotate thedevice during the implantation process and mistake one suture tab foranother. For example, it is possible to mistake the 6 o'clock suture tabwith an adjacent suture tab, such as a 4 or 8 o'clock suture. Thus,according to some embodiments, a tissue expansion device can be providedthat uses a visually distinctive, unique-looking, or differently coloredsuture tab at only a single position, such as at the 6 o'clock position.In this manner, a clinician can more clearly distinguish the suture tabsfrom each other and discern the proper orientation of the device duringthe procedure.

Additional features and advantages of the subject technology will be setforth in the description below, and in part will be apparent from thedescription, or may be learned by practice of the subject technology.The advantages of the subject technology will be realized and attainedby the structure particularly pointed out in the written description andembodiments hereof as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the subject technology.

BRIEF DESCRIPTION OF THE DRAWINGS

Various features of illustrative embodiments of the present disclosureare described below with reference to the drawings. The illustratedembodiments are intended to illustrate, but not to limit, the presentdisclosure. The drawings contain the following figures:

FIG. 1 is a perspective view of a tissue expansion device, according tosome embodiments.

FIG. 2 is a front view of the tissue expansion device of FIG. 1,according to some embodiments.

FIG. 3 is a rear plan view of the tissue expansion device of FIG. 1,according to some embodiments.

FIG. 4A is a partial side view of the tissue expansion device of FIG. 1,according to some embodiments.

FIG. 4B is an exploded and assembled view of a tab and engagementassembly of the tissue expansion device of FIG. 1, according to someembodiments.

FIG. 5 is a cross-sectional side view of the tissue expansion device ofFIG. 1 taken along section lines 5-5, according to some embodiments.

FIG. 6 is an exploded view of the tissue expansion device of FIG. 1,according to some embodiments.

FIG. 7A is a side view of a mandrel for manufacturing a tissue expansiondevice, according to some embodiments.

FIG. 7B is a front view of the mandrel of FIG. 7A, according to someembodiments.

FIG. 8 is a front view of an alternative embodiment of a tissueexpansion device, according to some embodiments.

FIG. 9 is a front view of an alternative embodiment of a tissueexpansion device, according to some embodiments.

FIG. 10 is a front view of an alternative embodiment of a tissueexpansion device, according to some embodiments.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are setforth to provide a full understanding of the subject technology. Itshould be understood that the subject technology may be practicedwithout some of these specific details. In other instances, well-knownstructures and techniques have not been shown in detail so as not toobscure the subject technology.

Further, while the present description sets forth specific details ofvarious embodiments, it will be appreciated that the description isillustrative only and should not be construed in any way as limiting.Additionally, it is contemplated that although particular embodiments ofthe present disclosure may be disclosed or shown in the context ofbreast reconstruction or augmentation, such embodiments can be used withvarious devices and implants. Furthermore, various applications of suchembodiments and modifications thereto, which may occur to those who areskilled in the art, are also encompassed by the general conceptsdescribed herein.

With reference now to the figures, FIG. 1 illustrates a perspective viewof a tissue expansion device 10 that can be used for temporary surgicalimplantation in a patient, preliminary to another procedure, such asbreast augmentation, breast reconstruction, or skin grafting. The tissueexpansion device 10 can be placed beneath the skin and left in place fora period of time to permit overlying tissue and skin to grow or adjustto a given volume of the tissue expansion device 10.

As shown in FIGS. 1 and 2, as necessary, a clinician can inject or fillthe tissue expansion device 10 with a fluid via an injection port 12 ofthe device 10. For example, a clinician can use a needle of a syringe topierce the tissue expansion device 10 within the injection port 12 inorder to fill the device 10. The injection port 12 can providecontrollable flow into or out of the tissue expansion device 10.Further, the injection port 12 can be self-sealing upon removal of theneedle.

As illustrated in FIG. 1, the tissue expansion device 10 can comprise ananterior portion 14, a posterior portion 16, an upper pole 20, and alower pole 22. Further, the tissue expansion device 10 can also comprisean expandable shell 30. The expandable shell 30, or portions thereof,can be formed from a biocompatible polymer material such as siliconerubber, a laminate of various forms of silicone, silicone copolymers,polyurethane, and various other elastomers in various combinations.

As shown in the front view of FIG. 2, the expandable shell 30 of thetissue expansion device 10 can define a midpoint or center position 18that lies at a position between the upper pole 20 and the lower pole 22.In some embodiments, the center position 18 of the expandable shell 30can be located at a geometric center of a circular shell. For example,FIG. 2 illustrates that the center position 18 is located at a midpointof the diameter between opposing edges, circumference, or boundaries ofthe expandable shell 30. However, in embodiments where the shell 30 isnot circular, the center position 18 need not represent a geometriccenter of the shell; for example, the center position 18 can represent amidpoint along a line (e.g., a height dimension or diameter) extendingfrom an edge of a top portion 24 of the shell 30 to an edge of a bottomportion 26 of the shell 30.

In accordance with at least one embodiment, an outer surface 32 of theshell 30 can have a smooth or glossy finish. The device 10 can be round,circular, oval, crescent-shaped, anatomically shaped, or other suitableshapes in order to mimic a natural or desired breast shape.

In at least one embodiment, the tissue expansion device 10 can comprisea plurality of tabs 40 coupled to the posterior portion 16 of the shell30. The tabs 40 can be used by the clinician to anchor, engage, orsecure the tissue expansion device 10 relative to the surrounding tissueat the implantation site of the patient. As shown in FIGS. 1 and 2, thetabs 40 can optionally comprise an aperture 42 through which a suture orother fastening means can be coupled to the tab 40 to facilitateanchoring of the tissue expansion device 10 to the patient's tissue.

Referring to FIG. 3, the tabs 40 can be circumferentially spaced apartabout the posterior portion of the shell 30. The tabs 40 can extend inradially outward direction relative to the center position 18 of theexpandable shell 30. For example, if the device 10 uses six tabs, thetabs 40 can be circumferentially spaced apart at an angle 50 ofapproximately 60°. However, if the device uses two, three, four, five,seven, eight, nine, ten, eleven, twelve, or more tabs, the tabs can bespaced apart at an angle 50 that is based on or corresponds to thenumber of tabs. For example, in at least one embodiment, the tabs can beequally circumferentially spaced apart depending on the number of tabs(e.g., the tabs are circumferentially spaced apart at an angle equal to360 degrees divided by the number of tabs), as in the embodimentillustrated in FIG. 3. Thus, in FIG. 3, the six tabs 40 are positionedcircumferentially about the posterior portion of the shell at a 12o'clock position, a 2 o'clock position, a 4 o'clock position, a 6o'clock position, an 8 o'clock position, and a 10 o'clock position,respectively.

Additionally, in at least one embodiment, one or more of the tabs cancomprise an attribute that is different from an attribute of one or moreof the other tabs. The attribute may comprise at least one of a color ofa tab, a size of a tab, a shape of the tab, or a material of a tab. Oneor more of the tabs can be differently colored or have a differentshape, size, or material than the one or more of the other tabs. In atleast one embodiment, one or more of the tabs can be white, tan, yellow,orange, red, pink, purple, blue, green, brown, gray, black, and/or anyshades thereof.

For example, in at least one embodiment having six tabs, a 6 o'clock tab60 can be white in color while the remainder of the tabs, positioned at12 o'clock, 2 o'clock, 4 o'clock, 8 o'clock, and 10 o'clock positions,can be blue.

Further, in at least one embodiment, all of the tabs except for one maybe white, while the other tab has a non-white color.

Furthermore, in at least one embodiment, one or more of the tabs can bea first color, one or more of the tabs can be a second color, or more ofthe tabs can be a third color, one or more the tabs can be a fourthcolor, one or more of the tabs can be a fifth color, and/or one or moreof the tabs can be a sixth color.

As discussed further herein, the distinguishing attribute(s) of one ormore tabs can help a clinician when placing the device 10 within thepatient. For example, the tabs 40 can help a clinician to identify ordiscern the top portion 24, and/or bottom portion 26, and/or a lateralportions 28 of the device 10. For example, the clinician can recognizethat the top portion 24 is adjacent the upper pole 20, the bottomportion 26 is adjacent the lower pole 22, and the lateral portions 28are positioned between the top and bottom portions, which can assist theclinician in positioning or aligning the device 10, thereby ensuringthat the shape of the device 10 is properly aligned relative to thepatient's body. Further, as disclosed in more detail herein, certainattributes, such as the color, texture, or shape of the tabs can bemodified or designed so as to help the clinician quickly identify thesection or portion of the device 10 at which a given tab resides.

For example, in order to assist a clinician in identifying or discerningthe top, bottom, and/or the alignment of the device 10, a plurality oftabs can be disposed about the top portion 24, the bottom portion 26,and/or the lateral portions 28 of the shell 30. In at least oneembodiment, six tabs are spaced at 12 o'clock, 2 o'clock, 4 o'clock, 6o'clock, 8 o'clock, and 10 o'clock positions, the tabs at the 4 o'clock,6 o'clock, 8 o'clock positions can be a first color while the tabs atthe 2 o'clock and 10 o'clock positions can be a second color.Optionally, the 12 o'clock tab can be either the first or second color.In such embodiments, the tabs at the 4 o'clock, 6 o'clock, and 8 o'clockpositions can serve to indicate a top or bottom of the device 10.Further, in embodiments in which the 12 o'clock tab is the first color(the same color as the tabs at the 4 o'clock, 6 o'clock, and 8 o'clockpositions), the clinician may be able to easily discern both the top andbottom of the device 10, as well as the alignment of the device 10.Additionally, in at least one embodiment, the color scheme may vary suchthat the tabs at the 4 o'clock and 8 o'clock positions have a differentcolor than the remainder of the tabs.

Optionally, the tissue expansion device 10 can also comprise anorientation indicator 70. As noted above, the present disclosure notesthe realization that if anatomically shaped, breast implants aregenerally symmetrical about a centerline and therefore, require thesurgeon to be aware of that centerline so the device is implanted in theproper orientation. Although certain tissue expansion devices havepreviously incorporated raised silicone dots on the surface of the shellto provide palpable and visual indicators or visible lines on the shellof contrasting color, such as blue or white, to indicate the centerline,these dots or lines are applied to the implant shell during secondaryassembly operations. Thus, the cost for manufacturing is high and theadditional material or color can be lost or may be inaccurately applied.As such, in addition to the challenge of properly aligning the tissueexpansion device or breast implant relative to the patient's anatomy,the manufacturing process that creates indicator dots and lines may beinadequate or inaccurate, which inaccuracies can be difficult for theclinician to appreciate or overcome. In contrast, the present disclosureprovides a solution that creates an orientation indicator 70 that isformed with and/or along an inner surface of the shell 30, therebyavoiding the additional manufacturing costs and ensuring that theorientation indicator 70 is accurately placed relative to the shell 30and its shape.

In at least one embodiment, the orientation indicator 70 is visiblealong the anterior portion 14 of the shell 30. The orientation indicator70 can be disposed along the lower pole 22 of the shell 30. However, theorientation indicator 70 can also extend along the upper pole 20 of theshell 30. Further, in some embodiments, the orientation indicator 70 canextend along both the upper pole 20 and the lower pole 22.

The orientation indicator 70 can extend to and/or beyond the centerposition 18 of the shell 30. Further, the orientation indicator 70 canextend through and beyond, through, or only up to the injection port 12.

As shown in FIG. 2, the orientation indicator 70 can extend as avertical line along a vertical dimension. However, the orientationindicator 70 can also extend as a generally horizontal line along ahorizontal dimension. The longitudinal extent of the orientationindicator 70 can correspond to a vertical or horizontal dimension. Forexample, referring to the front view of FIG. 2, the orientationindicator 70 can extend from the lower portion 26, upwardly across atleast 50% of the diameter or height of the expandable shell 30. Inaccordance with some embodiments, the orientation indicator 70 canextend up to about 50%, at least about 50%, at least about 55%, at leastabout 60%, at least about 65%, at least about 70%, at least about 75%,at least about 80%, at least about 85%, at least about 90%, at leastabout 95%, or up to the entirety of a given dimension, diameter, orheight of the expandable shell 30. The width, patterning, shape, and/orlongitudinal extent of the orientation indicator 70 can advantageouslybe designed to provide a ready visual tool for placing and aligning thedevice 10. This dedicated feature provide unique, cost-effectiveadvantages from both manufacturing and clinical perspectives.

The orientation indicator 70 can provide one or more geometric patternsor shapes that can allow the clinician to identify an aspect of and/orthe orientation of the tissue expansion device 10 during implantation ofthe device 10 within a cavity of a patient. As illustrated in FIG. 2,the orientation indicator 70 can comprise a band, strip, or line thatextends along and is visible along the shell 30. Further, theorientation indicator 70 can be aligned with one or more components oraspects of the tissue expansion device 10. For example, the orientationindicator 70 can be aligned with at least one of the plurality of tabs40. If a line or linear pattern, the orientation indicator 70 can extendalong a vertical, horizontal, or other axis. The visual perception ofthe orientation indicator 70 can enable a clinician to adjust a positionof the tissue expansion device 10 within the cavity by aligning theorientation indicator 70 relative to a horizontal or vertical plane orother indicia.

Although various configurations can be created, the embodiment shown inFIG. 2 illustrates that the orientation indicator 70 extends along agenerally vertical plane between an edge of the shell 30 adjacent to the6 o'clock tab 60 and the injection port 12. The orientation indicator 70can extend partially or fully along such a path, along the lower pole 22of the shell 30. Optionally, the orientation indicator 70 can extendalong the upper pole 20 along the same vertical plane. However, theembodiment illustrated in FIG. 2 advantageously provides a clearindication to the clinician as to the orientation of the tissueexpansion device 10 because it appears in only the lower pole 22 andalso provides a sufficiently long line as a visual indicator.

In some embodiments, the orientation indicator 70 comprises a linehaving a first end portion 72 adjacent to an edge of the shell 30 and asecond end portion 74 distal to the edge of the shell. The injectionport 12 can intersect with the second end portion of the orientationindicator 70. Optionally, the second end portion 74 of the orientationindicator extends to or is aligned with an outer perimeter 13 of theinjection port 12.

In accordance with some embodiments, advantageously, in addition tofacilitating alignment and proper placement of the device within apatient, the orientation indicator 70 can also be used to facilitatemanufacturing of the device 10. For example, the orientation indicator70 can be used to increase the manufacturing efficiency and accuracy ofeach device 10, as well as the manufacturing consistency betweenmultiple devices 10. For example, after the shell 30 is manufacturedwith the orientation indicator 70, the injection port 12 can bepositioned along the shell 30 by aligning a portion of the injectionport 12 with a portion of orientation indicator 70. For example, theouter perimeter 13 (e.g., a lowermost portion of the perimeter or acentral portion) of the injection port 12 can be placed so as to abut orotherwise be aligned with the second end portion 74 of the orientationindicator.

Referring now to FIGS. 3-4B, the tabs 40 can be coupled to the shell 30by an adhesive or co-molded with a portion of the shell 30. FIGS. 4A and4B illustrate a side view and perspective assembly views of a tab 40.FIG. 4A illustrates the 6 o'clock tab 60 and its engagement structure 80in side view. FIG. 4B illustrates an exploded view and an assembly viewof the engagement structure 80 with the tab 40. The engagement structure80 can comprise upper and lower engagement layers 82, 84 that sandwichthe tab 40 therebetween. The engagement structure 80 and the tab 40 canbe attached to the shell 30 and vulcanized. The tabs 40 can comprise asurface structure or mesh pattern along an outer surface thereof, whichcan assist in grasping the tab 40 in order to manipulate a position ofthe device 10 and two further enhance engagement with the upper andlower engagement layers 82, 84. As shown in FIG. 4A, the engagementstructure 80 and the tab 40 can be coupled to the posterior portion 16of the shell 30.

FIGS. 5 and 6 illustrate side cross-sectional views of the tissueexpansion device 10 in an assembled and an exploded state, respectively.As shown in FIG. 5, the injection port 12 of the device 10 be positionedwithin a cavity 90 of the shell 30. The injection port 12 can comprisean injection reservoir assembly 100 that is coupled to an inner surface102 of the shell 30. The injection reservoir assembly 100 can befabricated similar to that disclosed in U.S. Pat. No. 4,671,255, whichis owned by the present applicant, the entirety of which is incorporatedherein by reference.

In the present disclosure, the injection reservoir assembly 100 cancomprise an injection reservoir 110 that is coupled to or laminated ontothe inner surface 102 of the shell 30. The injection reservoir assembly100 can provide a self-sealing valve or injection port that will tend toseal any puncture or opening created by a needle when it is advancedinto and later withdrawn from the injection port 12.

FIG. 5 shows the upper pole 20 positioned between the center position 18of the shell 30 and a top edge of the shell 30 at the top portion 24,and the lower pole 22 positioned between the center position 18 of theshell 30 and a bottom edge of the shell 30 at the bottom portion 26. Theinjection port 12 can be positioned entirely within the upper pole 20.In some embodiments, however, only a portion of the injection port 12can be positioned within the upper pole 20, with a portion of theinjection port 12 extending across the center position 18. In someembodiments, at least 50% of the injection port 12 is positioned withinthe upper pole 20.

The orientation indicator 70 can extend from the injection port 12toward the bottom edge of the shell 30, as shown in the front view ofthe device 10 in FIG. 2. Further, in some embodiments, the orientationindicator 70 can extend from the injection port 12 toward another edgeof the shell 30, such as the top edge or a lateral edge of the shell 30.Additionally, in some embodiments, the orientation indicator 70 canextend from the injection port 12 across a portion of the upper pole 20and across the lower pole 22.

As shown in FIG. 6, the injection reservoir 110 can be coupled to theinner surface 102 via a coupling layer 112. In at least one embodiment,the coupling layer 112 can comprise a reinforced ring 114 and a fillerplug 116. The reinforced ring 114 can comprise a mesh or fabric materialthat is co-molded with a polymer, such as silicone. The reinforced ring114 can serve to increase the durability of the injection reservoirassembly 100. The reinforced ring 114 can optionally be configured as atear-resistant layer.

The injection reservoir 110 can include reservoir body 111 and a flange113 that extends radially outward from the reservoir body 111. Theflange 113 can comprise a thickness that tapers away from the reservoirbody 111. The reservoir body 111 can form an intermediate perimeter ofthe injection reservoir 110, while the flange 113 can form or extendalong the outer perimeter 13 of the injection port. When the orientationindicator 70 is used as a reference point during manufacturing, e.g., toposition the injection port 12, the flange 113 can be positioned toalign with the second end portion 74 of the orientation indicator whencoupling the injection reservoir 110 to the device 10.

The tapered flange 113 can provide a flexible (or alternatively, a morerigid) portion of the injection reservoir 110. For example, the flange113 can flex, relative to the reservoir body 111, thereby providing asmooth, less abrupt transition between the injection reservoir 110 andthe adjacent portion of the device 10. Thus, when a force (such as abending force or a point stress exerted against the shell 30) isdirected against the injection reservoir 110 or adjacent area thereto,the flange 113 can tend to flex or provide a rigid, tactilelydiscernible perimeter for the injection port 12. Additionally, theflange 113 provide an increased surface area, relative to the reservoirbody 111, to couple the injection reservoir 110 to the inner surface 102of the shell, thereby advantageously ensuring a greater seal between theinjection reservoir 110 and the inner surface 102. Thus, the material,structure, and radial extent of the flange 113 can be selected so as toprovide a desired amount of surface area and a desired structuralbehavior for the injection port 12.

The tissue expansion device 10 can also comprise a stable base 120 thatis coupled to the inner surface 102 of the shell 30 along the posteriorportion 16 of the shell. As shown, the shell 30 can comprise a mandrelaperture 122 that extends through the posterior portion of the shell 30.The stable base 120 can be coupled to the posterior portion 16 andprovide structural support thereto, especially around the mandrelaperture 122. Additionally, the tissue expansion device can comprise afiller plug 124 and a patch 126 that can be used to fill and seal themandrel aperture 122.

In accordance with at least one embodiment, as noted previously, theshell 30 can comprise an opaque or translucent appearance. In order toachieve the opaque or translucent appearance, the shell 30 can befabricated such that the inner surface 102 comprises a roughenedtexture. Thus, light passing through the shell 30 will be diffracted andthe passage of light will be impeded, thus achieving an opaque ortranslucent appearance of the shell 30.

In accordance with a realization of at least one embodiment disclosedherein, when the stable base 120 is coupled to or laminated against theinner surface 102 of the shell 30, many of the microscopic gaps andpockets of the roughened texture of the inner surface 102 will be filledin with and eliminated by material from the stable base 120 as a resultof the lamination process. As the roughened texture of the inner surface102 is eliminated through the lamination process, light diffraction willbe greatly reduced, thus creating a clear or transparent appearancealong these areas of coupling between the stable base 120 with the shell30. In some cases, the now-clear or transparent appearance along theseareas can tend to draw attention to any air pockets, striations,fractures, or other imperfections of the lamination between thesecomponents. Although a similar result may be detected in the laminationbetween the injection reservoir assembly 110 and the inner surface 102of the shell 30, the reinforced ring 114 may be configured to include amesh pattern that can tend to mask or disguise any visual imperfectionsin the lamination process.

To provide an attractive appearance and disguise any visualimperfections in the lamination between the stable base 120 and theinner surface 102 of the shell 30, at least one embodiment can beconfigured such that the stable base 120 comprises a textured innersurface 130. The textured inner surface 130 can provide a visuallysimilar appearance to the mesh pattern of the reinforced ring 114.Because the laminated stable base 120 and inner surface 102 will providea generally transparent view of the textured inner surface 130, thetissue expansion device can be provided with a consistent pattern alongthe injection port 12 in the anterior portion 14 of the device 10, theposterior portion 16, and the tabs 40. Further, although the pattern inthe illustrated embodiment is discussed as being a mesh pattern, otherpatterns can provided. Further, the pattern of the textured innersurface 130 can also be selected to be distinct from the patternprovided by the reinforced ring 114 at the injection port 12 and/or thetabs 40.

The shell 30 has a thickness extending between the outer surface and theinner surface 102 of the shell. The thickness of the shell can beapproximately constant along each of the anterior portion 14 and theposterior portion 16 of the device. The constant thickness of the shell30 can provide consistent light penetration and/or diffraction throughthe shell 30, and can provide consistent resistance along all portionsof the shell 30. However, in some embodiments, the thickness of theshell 30 can increase and/or decrease along any portion thereof. Forexample, the thickness of the shell 30 can decrease from the anteriorportion 14 toward the posterior portion 16. In some embodiments, thethickness of the shell 30 can decrease from the lower pole 22 toward theupper pole 20. Such variations in thickness can advantageously providedesired tactile feedback to assist the clinician in aligning the device10 relative to the anatomy of the patient.

When viewed in cross-section, such as shown in FIG. 5, the device 10 hasa width extending between the posterior portion 16 and the anteriorportion 14. The width of the device 10 tapers from the lower pole 22toward the upper pole 20. In some embodiments, when moving from thebottom portion 26 toward the top portion 24, the width of the device 10increases along the lower pole 22, and then the width of the device 10decreases along the upper pole 20. In some embodiments, the device 10has a maximum width at the lower pole 22, proximal to the centerposition 18, and a minimum width at the upper pole 20, adjacent to thetop portion 24.

In accordance with some embodiments, the outer surface of the shell 30along the anterior portion 14, can comprise a generally convex shape.However, it should be understood that a portion of the shell 30 can havea convex shape or a concave shape. For example, the outer surface of theshell 30 along a portion of the lower pole 22 can be convex, while theouter surface of the shell 30 along a portion of the upper pole 20 canbe concave. In some embodiments, the outer surface of the shell 30transitions from a convex shape to a concave shape along a portion ofthe upper pole 20.

Referring now to FIGS. 7A and 7B, a mandrel 150 is illustrated that canbe used in fabricating at least one embodiment disclosed herein. Thecasting tool or mandrel 150 can comprise an outer surface 152. Duringmanufacturing of the device 10, the mandrel 150 can be coupled toanother tool or support apparatus using a coupling recess 154 of themandrel. In some embodiments, the coupling recess 154 is positioned atthe center 156 of the mandrel. The coupling recess 154 can correspond tothe mandrel aperture 122 of a shell, and the center 156 of the mandrelcan correspond to the center position 18 of a shell, such as the shell30 discussed in the embodiment of FIGS. 1-6.

As shown in front view of the mandrel 150 in FIG. 7B, the outer surface152 can have a smooth region 160 and a roughened region 162. The smoothregion 160 can correspond to an orientation indicator, such as theorientation indicator 70 discussed in the embodiment of FIGS. 1-6. Insome embodiments, a roughened region of the outer surface 152 cancorrespond to an orientation indicator, and another portion of the outersurface 152 can have a smooth region. FIG. 7B also demonstrates how thesmooth region 160, which can correspond to an orientation indicator,extends across the center 156 of the mandrel, which can correspond to acenter position 18 of a shell.

In accordance with at least one method of manufacturing the tissueexpansion device 10, the mandrel 150 can be dipped into a polymersolution and subsequently dried, which can produce a shell. The shellwill have a shape consistent with the shape of the outer surface 152 ofthe mandrel 150. However, in addition, the shell can have an innersurface that corresponds to the smooth region 160 and the roughenedregion 162 of the outer surface 152 of the mandrel 150. In this manner,a desired texture of the inner surface 102 of the shell 30 discussedabove, as well as any shape or pattern of the orientation indicator 70,can be achieved. In this manner, various advantages can be achieved overprior devices and methods of manufacture.

FIGS. 8, 9, and 10 illustrate different embodiments of the tissueexpansion device 10. For example, FIG. 8 illustrates an embodiment of atissue expansion device 170 that comprises a plurality of tabs 40, anorientation indicator 70, and other such features similar to the tissueexpansion device 10, details of which will not be discussed herein forbrevity, but are incorporated by reference from the disclosure above.However, the device 170 can be configured to comprise an injection port172 having a visible or tactile outer ring 174. The injection port 172can be compact and have a coupling area along the outer ring 174 that issmaller in size than that of the injection port 12.

Referring to FIG. 9, in embodiment of a tissue expansion device 180 isillustrated in which the device 180 does not comprise tabs. Features ofthe device 180 can be similar to those discussed above with respect tothe device 10 and are not discussed herein for brevity, but areincorporated by reference from the disclosure above. However, the device180 can be manufactured and used without the tabs disclosed above withrespect to the device 10. Further, although the device 180 can beconfigured without any tabs, other embodiments can be configured toinclude one or more tabs, as disclosed herein.

For example, FIG. 10 illustrates an embodiment of a tissue expansiondevice 190 that comprises three tabs that are circumferentially offsetat 120° from each other. Features of the device 190 can be similar tothose discussed above with respect to the device 10 and are notdiscussed herein for brevity, but are incorporated by reference from thedisclosure above. Further, the injection port 192 can form a transparentor opaque, nonwhite portion of the device 190 without any underlyingpattern from a reinforced ring. Further, the device 190 can beconfigured to comprise a corresponding or different appearance of theposterior portion and/or tabs of the device relative to the injectionport 192.

Further Considerations

In some embodiments, any of the clauses herein may depend from any oneof the independent clauses or any one of the dependent clauses. In oneaspect, any of the clauses (e.g., dependent or independent clauses) maybe combined with any other one or more clauses (e.g., dependent orindependent clauses). In one aspect, a claim may include some or all ofthe words (e.g., steps, operations, means or components) recited in aclause, a sentence, a phrase or a paragraph. In one aspect, a claim mayinclude some or all of the words recited in one or more clauses,sentences, phrases or paragraphs. In one aspect, some of the words ineach of the clauses, sentences, phrases or paragraphs may be removed. Inone aspect, additional words or elements may be added to a clause, asentence, a phrase or a paragraph. In one aspect, the subject technologymay be implemented without utilizing some of the components, elements,functions or operations described herein. In one aspect, the subjecttechnology may be implemented utilizing additional components, elements,functions or operations.

The subject technology is illustrated, for example, according to variousaspects described below. Various examples of aspects of the subjecttechnology are described as numbered clauses (1, 2, 3, etc.) forconvenience. These are provided as examples and do not limit the subjecttechnology. It is noted that any of the dependent clauses may becombined in any combination, and placed into a respective independentclause, e.g., clause 1 or clause 5. The other clauses can be presentedin a similar manner.

Clause 1. A tissue expansion device for temporary surgical implantationbeneath skin of a patient and for removal upon predetermined expansionof overlying tissue, the device comprising: an expandable shell formingan expandable chamber, the shell having an anterior portion and aposterior portion; an orientation indicator visible along the anteriorportion of the expandable shell, wherein, when the expandable shellexpandable shell is viewed from the front, the orientation indicatorextends across at least 50% of a vertical dimension of the expandableshell; and an injection port, coupled to the anterior portion of theshell, in fluid communication with the chamber and configured to permitinjection of fluid into the chamber from a hypodermic needle.

Clause 2. The device of Clause 1, further comprising a plurality of tabscoupled to the posterior portion of the shell.

Clause 3. The device of Clause 1, further comprising a plurality of tabsdisposed about top, bottom, and lateral portions of the expandableshell.

Clause 4. The device of Clause 2, wherein each of the plurality of tabsextends in radially outward direction relative to a center position ofthe device.

Clause 5. The device of any one of Clauses 2-4, wherein the plurality oftabs comprises six tabs.

Clause 6. The device of any one of Clauses 2-5, wherein the plurality oftabs comprises six tabs, and wherein the six tabs are positionedcircumferentially about the posterior portion of the shell at a 12o'clock position, a 2 o'clock position, a 4 o'clock position, a 6o'clock position, an 8 o'clock position, and a 10 o'clock position,respectively.

Clause 7. The device of any one of Clauses 2-6, wherein at least one ofthe plurality of tabs comprises an attribute different from an attributeof a remainder of the plurality of tabs.

Clause 8. The device of Clause 7, wherein the attribute comprises atleast one of a color of the tab, a size of the tab, a shape of the tab,or a material of the tab.

Clause 9. The device of any one of Clauses 2-8, wherein the plurality oftabs comprises six tabs, and wherein a first of the six tabs has a firstcolor and a remainder of the six tabs has a second color.

Clause 10. The device of Clause 9, wherein the first of the six tabs ispositioned at a bottom portion of the expandable shell.

Clause 11. The device of any one of Clauses 2-10, wherein each of theplurality of tabs comprises an aperture for receiving a suturetherethrough.

Clause 12. The device of any one of Clauses 1-11, wherein theorientation indicator is formed along an inner surface of the shell.

Clause 13. The device of any one of Clauses 1-12, wherein theorientation indicator comprises a line.

Clause 14. The device of any one of Clauses 1-13, wherein theorientation indicator comprises a line extending from the injection porttoward an edge of the shell.

Clause 15. The device of any one of Clauses 1-14, wherein theorientation indicator extends across at least about 50% of a dimensionof the expandable shell.

Clause 16. The device of any one of Clauses 1-15, wherein theorientation indicator extends across at least about 55% of a dimensionof the expandable shell.

Clause 17. The device of any one of Clauses 1-16, wherein theorientation indicator extends across at least about 60% of a dimensionof the expandable shell.

Clause 18. The device of any one of Clauses 1-17, wherein theorientation indicator extends across at least about 65% of a dimensionof the expandable shell.

Clause 19. The device of any one of Clauses 1-18, wherein theorientation indicator extends across at least about 70% of a dimensionof the expandable shell.

Clause 20. The device of any one of Clauses 1-19, wherein theorientation indicator extends across at least about 75% of a dimensionof the expandable shell.

Clause 21. The device of any one of Clauses 1-17, wherein theorientation indicator extends across a center position of the expandableshell.

Clause 22. The device of any one of Clauses 1-14, wherein theorientation indicator extends across at least about 50% of a verticaldimension of the expandable shell.

Clause 23. The device of Clause 1, further comprising a plurality oftabs coupled to the posterior portion of the shell, wherein a first tabof the plurality of tabs is coupled to the shell at a 6 o'clockposition, and wherein the orientation line extends from the injectionport toward the first tab at the 6 o'clock position.

Clause 24. The device of Clause 1, further comprising a plurality oftabs coupled to the posterior portion of the shell, wherein theorientation indicator is aligned with at least one of the plurality oftabs.

Clause 25. The device of any one of Clauses 1-24, wherein theorientation indicator comprises a surface texture of the expandableshell.

Clause 26. The device of any one of Clauses 1-25, wherein theorientation indicator comprises a surface texture of an interior surfaceof the expandable shell.

Clause 27. The device of any one of Clauses 1-26, wherein an exteriorsurface of the expandable shell comprises a smooth finish, theorientation indicator comprises a smooth finish on an interior surfaceof the expandable shell, and a remainder of the interior surface of theexpandable shell comprises a roughened finish.

Clause 28. The device of any one of Clauses 1-27, wherein theorientation indicator comprises a line having a first end portionadjacent to an edge of the shell and a second end portion distal to theedge of the shell, and wherein the second end portion intersects theinjection port.

Clause 29. The device of Clause 28, wherein the second end portion ofthe orientation indicator is aligned with an outer perimeter of theinjection port.

Clause 30. The device of any one of Clauses 1-29, wherein theorientation indicator is a transparent portion of the shell.

Clause 31. The device of any of the preceding Clauses, wherein an outersurface of the shell comprises a smooth finish.

Clause 32. A method of implanting the tissue expansion device of any ofthe preceding Clauses, the method comprising: positioning the tissueexpansion device within a cavity of a patient; and adjusting a positionof the tissue expansion device within the cavity by aligning anorientation indicator relative to a horizontal or vertical plane.

Clause 33. The method of Clause 32, wherein the orientation indicatorcomprises a transparent portion of the shell of the tissue expansiondevice, and the adjusting comprises aligning the orientation indicatorrelative to a vertical plane.

Clause 34. The method of Clause 33, wherein tissue expansion devicecomprises a plurality of tabs coupled to a posterior portion thereof,and wherein the orientation indicator is aligned with a first tab of theplurality of tabs located at a 6 o'clock position, and the adjustingcomprises aligning the orientation indicator and the first tab relativeto a vertical plane.

Clause 35. A method of manufacturing a tissue expansion device, themethod comprising: dipping a casting tool into a polymer solution toform a shell along an outer surface of the casting tool, the castingtool outer surface having a textured portion and a smooth portion;permitting the shell to dry; and removing the shell from the castingtool, the shell having an inner surface comprising a first portioncorresponding to the textured portion and a second portion correspondingto the smooth portion, the shell having a smooth outer surface, whereinthe smooth outer surface of the shell and the second portioncollectively define a transparent orientation indicator, and wherein thesmooth outer surface of the shell and the first portion of the shellinner surface collectively define a translucent or opaque section of theshell that visually contrasts against the transparent orientationindicator, wherein the orientation indicator extends across at least 50%of a diameter of the expandable shell.

Clause 36. The method of Clause 35, further comprising coupling aplurality of tabs to a posterior portion of the shell.

Clause 37. The method of Clause 36, wherein the coupling comprisescoupling the plurality of tabs circumferentially about the posteriorportion of the shell at a 12 o'clock position, a 2 o'clock position, a 4o'clock position, a 6 o'clock position, an 8 o'clock position, and a 10o'clock position, respectively.

Clause 38. The method of Clause 37, wherein a first tab of the pluralityof tabs comprises an attribute different from an attribute of aremainder of the plurality of tabs, and wherein the method furthercomprises positioning the first tab at a 6 o'clock position on theposterior portion of the shell.

Clause 39. The method of Clause 38, wherein the attribute comprises atleast one of a color of the tab, a size of the tab, a shape of the tab,or a material of the tab.

Clause 40. The method of any of Clauses 35-39, further comprisingcoupling an injection reservoir assembly to the shell inner surface atan injection port section of the shell inner surface to change thetranslucent or opaque section to transparent along the injection portsection.

Clause 41. The method of Clause 40, wherein the injection reservoirassembly comprises a reinforced ring having a first pattern formedtherein, the first pattern being visible through the transparentinjection port section when the injection reservoir assembly is coupledto the shell.

Clause 42. The method of Clause 41, wherein the first pattern comprisesa mesh pattern.

Clause 43. The method of any of Clauses 35-42, further comprisingcoupling a stable base to the shell inner surface along a posteriorportion of the shell to change the translucent or opaque section totransparent along a section of the posterior portion.

Clause 44. The method of Clause 43, wherein the stable base comprises apatterned internal surface having a second pattern formed therein, thesecond pattern being visible through the transparent section of theposterior portion when the stable base is coupled to the shell.

Clause 45. The method of Clause 44, wherein the second pattern comprisesa mesh pattern.

Clause 46. The method of any of Clauses 35-45, further comprisingcoupling an injection reservoir assembly to the shell inner surface atan injection port section of the shell, wherein coupling the injectionreservoir assembly comprises aligning an outer perimeter of theinjection reservoir with an end portion of the orientation indicator.

The foregoing description is provided to enable a person skilled in theart to practice the various configurations described herein. While thesubject technology has been particularly described with reference to thevarious figures and configurations, it should be understood that theseare for illustration purposes only and should not be taken as limitingthe scope of the subject technology.

There may be many other ways to implement the subject technology.Various functions and elements described herein may be partitioneddifferently from those shown without departing from the scope of thesubject technology. Various modifications to these configurations willbe readily apparent to those skilled in the art, and generic principlesdefined herein may be applied to other configurations. Thus, manychanges and modifications may be made to the subject technology, by onehaving ordinary skill in the art, without departing from the scope ofthe subject technology.

It is understood that the specific order or hierarchy of steps in theprocesses disclosed is an illustration of exemplary approaches. Basedupon design preferences, it is understood that the specific order orhierarchy of steps in the processes may be rearranged. Some of the stepsmay be performed simultaneously. The accompanying method claims presentelements of the various steps in a sample order, and are not meant to belimited to the specific order or hierarchy presented.

As used herein, the phrase “at least one of” preceding a series ofitems, with the term “and” or “or” to separate any of the items,modifies the list as a whole, rather than each member of the list (i.e.,each item). The phrase “at least one of” does not require selection ofat least one of each item listed; rather, the phrase allows a meaningthat includes at least one of any one of the items, and/or at least oneof any combination of the items, and/or at least one of each of theitems. By way of example, the phrases “at least one of A, B, and C” or“at least one of A, B, or C” each refer to only A, only B, or only C;any combination of A, B, and C; and/or at least one of each of A, B, andC.

Terms such as “top,” “bottom,” “front,” “rear” and the like as used inthis disclosure should be understood as referring to an arbitrary frameof reference, rather than to the ordinary gravitational frame ofreference. Thus, a top surface, a bottom surface, a front surface, and arear surface may extend upwardly, downwardly, diagonally, orhorizontally in a gravitational frame of reference.

Furthermore, to the extent that the term “include,” “have,” or the likeis used in the description or the claims, such term is intended to beinclusive in a manner similar to the term “comprise” as “comprise” isinterpreted when employed as a transitional word in a claim.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any embodiment described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments.

A reference to an element in the singular is not intended to mean “oneand only one” unless specifically stated, but rather “one or more.”Pronouns in the masculine (e.g., his) include the feminine and neutergender (e.g., her and its) and vice versa. The term “some” refers to oneor more. Underlined and/or italicized headings and subheadings are usedfor convenience only, do not limit the subject technology, and are notreferred to in connection with the interpretation of the description ofthe subject technology. All structural and functional equivalents to theelements of the various configurations described throughout thisdisclosure that are known or later come to be known to those of ordinaryskill in the art are expressly incorporated herein by reference andintended to be encompassed by the subject technology. Moreover, nothingdisclosed herein is intended to be dedicated to the public regardless ofwhether such disclosure is explicitly recited in the above description.

What is claimed is:
 1. A tissue expansion device for temporary surgicalimplantation beneath skin of a patient and for removal upon expansion ofoverlying tissue, the device comprising: an expandable shell having anexpandable chamber, an anterior portion, and a posterior portion; aplurality of tabs coupled to the posterior portion of the expandableshell, wherein a first tab of the plurality of tabs comprises a firstcolor different from a second color of a remainder of the plurality oftabs; and an injection port configured to permit injection of fluid intothe expandable chamber.
 2. The device of claim 1, wherein the firstcolor is any of white or transparent, and the second color is non-whiteor transparent.
 3. The device of claim 1, wherein the second color isblue.
 4. The device of claim 1, wherein the first tab comprises anattribute different from the other of the plurality of tabs.
 5. Thedevice of claim 4, wherein the attribute consists of at least one a sizeof the tab, a shape of the tab, or a material of the tab.
 6. The deviceof claim 1, wherein the first tab is positioned at a bottom portion ofthe expandable shell.
 7. The device of claim 1, wherein each of theplurality of tabs extends in radially outward direction relative to acenter position of the device.
 8. The device of claim 7, wherein theplurality of tabs are positioned circumferentially about the posteriorportion of the expandable shell, and each of the plurality of tabs arespaced apart from an adjacent tab of the plurality of tabs byapproximately 60 degrees.
 9. The device of claim 1, wherein theplurality of tabs comprises six tabs, and wherein the six tabs arepositioned circumferentially about the posterior portion of theexpandable shell at a 12 o'clock position, a 2 o'clock position, a 4o'clock position, a 6 o'clock position, an 8 o'clock position, and a 10o'clock position, respectively.
 10. The device of claim 9, wherein thefirst tab is positioned at the 6 o'clock position.
 11. A tissueexpansion device for temporary surgical implantation beneath skin of apatient and for removal upon expansion of overlying tissue, the devicecomprising: an expandable shell comprising contrasting surface texturesalong an interior surface thereof that collectively form an orientationindicator that is visible along an anterior portion of the expandableshell for facilitating alignment of the expandable shell relative tosurrounding tissue during placement; and an injection port configured topermit injection of fluid into the expandable shell from a hypodermicneedle.
 12. The device of claim 11, wherein the surface texturescomprise a smooth vertical strip flanked by textured areas.
 13. Thedevice of claim 11, wherein when the expandable shell is seen in frontview, the orientation indicator extends across at least 50% of avertical dimension of the expandable shell.
 14. The device of claim 11,wherein the expandable shell comprises a layer of polymer material, andthe orientation indicator is coextensive with the layer of polymermaterial.
 15. The device of claim 11, wherein the expandable shell, whenseen in front view, comprises a center position, a top portion, and abottom portion, and wherein at least a portion of the injection port ispositioned between the top portion and center position.
 16. The deviceof claim 11, wherein the orientation indicator comprises a verticalstrip having a first end portion adjacent to an edge of the expandableshell and a second end portion distal to the edge of the expandableshell.
 17. The device of claim 16, wherein the second end portion of theorientation indicator intersects the injection port.
 18. The device ofclaim 16, wherein the first end portion of the orientation indicator isaligned with a first tab of a plurality of tabs coupled to theexpandable shell.
 19. The device of claim 16, wherein the second endportion of the orientation indicator extends around an outer perimeterof the injection port.